5-{[(2S)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-4-(methylsulfanyl)butanamido]methyl}furan-2-carboxylic acid

2-(7-{1-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]cyclopropanecarbonyl}-7-azabicyclo[2.2.1]heptan-1-yl)acetic acid

2-{7-[2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)-2-methylbutanoyl]-7-azabicyclo[2.2.1]heptan-1-yl}acetic acid

4-[(2S,3R)-3-(tert-butoxy)-2-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)butanamido]but-2-ynoic acid

4-{[4-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)but-2-ynamido]methyl}cyclohexane-1-carboxylic acid

(3R)-1-[4-({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)but-2-ynoyl]piperidine-3-carboxylic acid

rac-1-[(3R,5R)-5-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]oxolane-3-carbonyl]-3-methylpyrrolidine-2-carboxylic acid

3-(N-benzyl-1-{3-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]cyclohexyl}formamido)propanoic acid

rac-3-cyclopropyl-3-{[(3R,5R)-5-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]oxolan-3-yl]formamido}propanoic acid

rac-3-cyclopropyl-2-{[(3R,5R)-5-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]oxolan-3-yl]formamido}propanoic acid

rac-4-[(3R,5R)-5-[({[(9H-fluoren-9-yl)methoxy]carbonyl}amino)methyl]oxolane-3-carbonyl]thiomorpholine-3-carboxylic acid